Frangible non-lethal projectile

ABSTRACT

A non-lethal impact projectile having a nose composed of a frangible, rigid, polymer foam material such that the nose crushes upon impact with a target to disperse energy, thereby reducing the kinetic energy transferred to the target. Most preferably, the munition or projectile is provided with a cavity to retain a payload, such as marker agents, lacrimators, irritants, inflammatory agents, odorants or inert powders, such that the payload is laterally dispersed upon impact to further dissipate energy transferred to the target.

BACKGROUND OF THE INVENTION

This invention relates generally to the field of non-lethal projectilesor impact munitions and more particularly relates to the field of suchprojectiles capable of delivering a gas, powder or liquid payload. Evenmore particularly, the invention relates to such projectiles having arigid, frangible nose.

It is often desirable to provide for law enforcement, corrections ormilitary users a relatively low-impact, non-lethal projectile for usewith firearms or launchers, where the projectile is capable of impartingblunt trauma without deadly force and is also capable of delivering apayload for dispersion upon impact, the payload comprising a gas, liquidor powder having certain desired properties. Such munitions are used forexample in crowd control and other special operations, where it isdesirable to deter certain activity without utilizing lethal force. Thepayload may comprise for example marker agents, lacrimators, irritants,inflammatory agents, odorants and the like.

Since the projectile is designed to be direct-fired at the human target,it is necessary to insure that the impact force is sufficient to deliverenough pain to the target for compliance, but without causing seriousinjury. This is accomplished through the structural design of theprojectile as well as by limiting the projectile velocity. Reducing thevelocity of the projectile also reduces the accuracy of the trajectory,so a minimum acceptable velocity must be retained. By producing anenergy absorbing projectile, sufficient velocity may be maintained foraccuracy.

In order to achieve the desired results, projectiles have been developedwhere the entire projectile or at least the nose of the projectile isformed of a compliant, resilient material that compresses upon impact.The compliant material may take the form of a sphere. Alternatively, thenose of the projectile may be formed of a rubber, sponge or compliantfoam material that dissipates impact energy due to compressive elasticdeformation. Examples of such projectiles are shown in U.S. Pat. No.3,714,896 to Young and U.S. Pat. No. 6,041,712 to Lyon. A problem canoccur with the use of compliant nose materials in that the resilience ofthe material is detrimental to projectile accuracy due to adverseaerodynamic effects on the non-rigid nose. In addition, the use ofcompliant or soft materials to retain gas, liquid or powder payloadscreates problems in handling and storage, since the projectiles arereadily subject to accidental failure, resulting in unwanted dispersalof the payload. Likewise, environmental degradation will more rapidlyaffect the resilient material containing the payload.

It is also known to produce low-impact, non-lethal projectiles adaptedto carry payloads for dispersal on impact where the projectile or thenose of the projectile is made of a frangible material that breaks uponimpact as a result of compressive plastic deformation. For example, U.S.Pat. No. 6,145,411 to Woddall et al. shows a payload carrying sphericalprojectile formed of a rigid plastic material and provided with dimplesand score lines to create localized stress points that fracture uponimpact. The dimples and score lines also create a more accuratespherical projectile through aerodynamic effects. Another example isshown in U.S. Pat. No. 5,035,183 to Luxton, where a projectile havingthe typical bullet-shape is provided, the projectile being composed of arigid plastic material. Score lines are provided on the projectile suchthat it will rupture on impact. While the projectile accuracy is morereadily maintained in these designs, the energy dissipation at impact isrelatively small and remains concentrated, and the material ofconstruction is more likely to result in injury to the human targetsince breaking of the projectile results in jagged or sharp edges ofrelatively non-compliant material. In addition, these projectiles aremore likely to deliver serious injury if utilized at short range.

It is an object of this invention to provide a non-lethal, low-impactprojectile capable of delivering blunt trauma of sufficient amount toinduce compliance as well as to deliver a payload of a gas, liquid orpowder substance having desired effects on the human target. It is afurther object to provide such a projectile that overcomes the drawbacksinherent in the known systems. These and other objects that will becomeapparent from the disclosure to follow are accomplished by providing aprojectile having a nose formed in an aerodynamically preferredconfiguration and composed of a frangible, rigid foam material, suchthat impact energy is dissipated through plastic deformation of thenose, which first compresses and then breaks to disperse the payload.The projectile is capable of being mounted onto known projectiledelivery systems for use in known firearms, launchers or the like.

SUMMARY OF THE INVENTION

The invention comprises in general a non-lethal impact munition orprojectile adapted to be discharged from a firearm or other launcherdevice and directed at a human target, wherein the impact energy of theprojectile is below the threshold where serious injury or death wouldresult from the impact, yet is of sufficient force such that blunttrauma is delivered for the purpose of pain compliance. The design andstructure of the projectile is such that aerodynamic properties andprojectile velocity are not excessively adversely affected in order tomaintain the accuracy of delivery.

The projectile comprises a projectile nose mounted onto a projectilebase, wherein the nose is composed of a frangible, rigid, polymer foammaterial, such as polyurethane. The nose has a rounded forward end and acylindrical wall, and the base has a generally flat forward wall and acylindrical rear wall, adapted to be separably joined to a propulsionshell or casing to form a munition or cartridge capable of beingdischarged from a firearm or launcher by propulsion means within thepropulsion shell, the projectile having a typical bullet shape foraerodynamic purposes. The polymer foam material composing the nose issufficiently rigid so as to maintain its structural configuration duringdischarge and flight, but which is crushed and broken upon impact with ahuman target such that the impact energy is dissipated or reduced.Preferably, the forward end of the nose is thicker than the cylindricalwall of the nose, such that the compression and fracture occurs mainlyin the cylindrical wall. The nose may further comprise a rear plug wallthat is directly joined to the forward wall of the projectile base, withthe rear plug wall being preferably composed of a resilient, compliantpolymer or rubber material.

The projectile nose further comprises a cavity adapted to receive apayload to be dispersed upon impact with the human target. The payloadis chosen for a particular purpose and may consist of marker agents,lacrimators, irritants, inflammatory agents, odorants, inert powders orother materials. The crushing and fracture of the projectile nose uponimpact laterally expels or disperses the payload, which further reducesthe impact energy delivered to the target.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external view of the invention.

FIG. 2 is a cross-sectional view of the invention taken along line II-IIof FIG. 1.

FIG. 3 is a view of the projectile at impact showing dispersal of apayload.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, the invention will now be described withregard for the best mode and the preferred embodiment, but with theunderstanding that the scope of the patent is not limited to such andthat other variations and embodiments are covered by the language of theclaims. In a most general sense, the invention is a projectile, or theprojectile in combination with a casing or shell to define an impactmunition, to be discharged or propelled from a firearm or similarlauncher device such that the projectile is accurately delivered toimpact a target, and in particular such that the projectile can strike ahuman target without inflicting death or serious bodily injury, yet willhave sufficient impact force to deliver blunt trauma in an amountdesigned to inflict sufficient pain so as to cause compliance by thetarget. In addition, the projectile is designed to be capable ofdelivering and dispersing upon impact a payload material, such as aliquid, gas or solid, the energy required for payload dispersal actingto further reduce the impact force. To accomplish these purposes, atleast a portion of the projectile is designed to crush and fracture uponimpact such that some of the impact energy is dissipated.

The structure of the invention must take into account severalconflicting and competing requirements for effective operation. The paininflicted by the projectile at impact must be sufficient enough to forcecompliance, yet the impact energy delivered to the target must be lowenough to prevent serious energy. Projectile accuracy must be maintainedthrough the aerodynamic design of the projectile as well as bymaintaining sufficient projectile velocity upon discharge.

FIGS. 1 and 2 show an external view and a cross-sectional view of thecomplete impact munition or cartridge of the invention, which is definedto comprise in combination a propulsion casing or shell 10 and aprojectile comprising a projectile base 20 and a projectile nose 30. Theimpact munition is constructed so as to be useable in firearms orlaunchers of known type, especially those firearms or launchers havingrifled barrels, such as for example a 40 mm rifled-barrel gas gun or anM203 rifled grenade launcher. The dimensions of the cartridge may varyto accommodate launchers of different caliber (37 mm, 66 mm, etc.), aswell as shotguns of varying gauges. The propulsion shell 10 may be ofknown type, and is shown to comprise an annular forward wall 14 having aforward shell rim 16 and joined to a shell base 11 having a rear wall17. A co-axially oriented propulsion cavity 12 is disposed in the shellbase 11 and retains propulsion means 13 of known type, preferably asmokeless system. The annular forward wall 14 defines a shell cavity 15to receive the expanding gases produced by the propulsion means 13 atdischarge.

Mounted in separable manner onto the front of the propulsion shell 10 isa projectile comprised of a projectile base 20 joined to a projectilenose 30. The projectile base 20, preferably composed of a polycarbonatematerial, comprises a domed forward end 21 joined to a cylindrical wall22 such that the combination defines a projectile cavity 23. Theexterior of the cylindrical wall 22 is provided with an undercut 24 thatdefines a rearward extending annular insertion flange 25. The insertionflange 25 is received within the shell rim 16 and shell forward wall 14in a male-female coupling, such that the projectile cavity 23 and theshell cavity 15 combine to form a single larger cavity.

The projectile nose 30 comprises a rounded forward end 31 combined witha cylindrical wall 32 and is composed of a substantially non-compliant,frangible, rigid, polymer foam material, most preferably a closed-cellpolyurethane. The rigidity of the foam must be sufficient for it toretain its structural configuration upon discharge and during flight soas not to adversely affect accuracy, yet be below a rigidity thresholdsuch that the foam is crushed and broken upon impact with soft tissue ofa human target in order to dissipate the energy. In other words, thefoam must undergo plastic deformation upon impact rather than elasticdeformation. It has been found that a polyurethane foam having a densitybetween approximately eight and 14 pounds per cubic foot used to formthe forward end 31 and cylindrical wall 32 provides these desiredcharacteristics. The thickness or radial dimension of the cylindricalwall 32 is preferably less than the thickness of the forward end.Through this construction, it is the cylindrical wall 32 that willdeform, crush and break upon impact of the projectile with the target99. The precise shape of the rounded forward end 31 is determined byaerodynamic characteristics well known in the art.

The combination of the forward end 31 and cylindrical wall 32 define anose cavity 33 that may be empty or that may receive a payload 35 to bedispersed or expelled when the nose 30 is crushed and broken upon impactwith the target 99. The payload 35 may comprise a gas, liquid, solid orpowder that possesses certain desirable properties when the payload 35is exposed to the target 99. For example, the payload 35 may comprisealone or in combination a marker agent, a lacrimator, an irritant, aninflammatory agent, an odorant or other material. Likewise, the payload35 may consist entirely of or include an inert powder. The presence of apayload 35 is preferable since energy is required to laterally dispersethe payload 35 upon impact, and this mass dispersion energy furtherreduces the momentum energy transferred from the projectile nose 30 tothe target 99. This allows the velocity to be increased slightlyrelative to an empty projectile nose 30 without increasing the kineticenergy transferred to the target 99.

Preferably, the nose 30 further comprises a rear plug wall 34 attachedto the rearward end of the cylindrical wall 32 that seals cavity 33.This allows the nose 30 to be manufactured by loading the payload 35into the cavity 33 and then attaching plug wall 34, by adhesives orother suitable means, prior to attachment to the projectile base 20.Preferably, the rear plug wall 34 is composed of a resilient, compliantpolymer or rubber material to further absorb impact energy and toprevent contact of the projectile base 20 with the target 99. The rearplug wall 34 is joined to the face of the base forward wall 21 byadhesives or other suitable means.

At discharge, the projectile base 20 and nose 30 separate from the shell10 in known manner and travel such that the nose forward end 31 strikesthe target 99, as shown in FIG. 3. Upon impact the rigid foam forwardend 31 is pushed to the rear toward the forward wall 21 of theprojectile base 20. The rigid foam cylindrical wall 32 of the nose 30,being of thinner dimension than the forward end 31, crushes and breakssuch that openings or tears are created. This absorbs and dissipatesenergy that would normally be delivered to the target 99. Any payload 35retained within nose cavity 33 will be expelled laterally in multipledirections.

The use of a closed-cell polyurethane foam or a polymer foam possessingsimilar characteristics to form the crushable components of the nose 30has been found to be advantageous for several reasons. The density ofthe foam is easily controlled during the molding process, which can beperformed by reaction injection molding. Specific shapes, contours andcavities are easily produced such that the external aerodynamic contourmay be maximized for best accuracy. The polymer foam material is inertto most payloads and is suitable for retention of gas or liquid as wellas a solid or powder. The rigid foam first deforms at impact throughcompression of air trapped within the cell walls and then breakage ofthe cell walls themselves, followed by rupture of the foam on a macroscale. The foam nose 30 is sufficiently structurally strong such that itis unlikely to break upon minor impacts that may occur during storage orhandling. After deformation and discharge of the payload 35, the crushedforward end 31 and cylindrical wall 32 form in combination with theresilient plug wall 34 a buffer or cushion between the projectile base20 and the target 99. This distributes the impact energy over themaximum surface area of the projectile, thereby minimizing the chance ofpenetration by the projectile base 20 into the target 99.

It is understood and contemplated that equivalents and substitutions forcertain elements set forth above may be obvious to those skilled in theart, and therefore the true scope and definition of the invention is tobe as set forth in the following claims.

1. A non-lethal projectile comprising: a projectile nose joined to aprojectile base; said projectile nose comprising a cavity; a payloaddisposed within said cavity; and said projectile nose composed of afrangible, rigid, polymer foam material; wherein said projectile nosehas a rounded forward end and a cylindrical wall, said cylindrical wallbeing thinner than said forward end, such that said thinner cylindricalwall breaks prior to said forward end upon impact to absorb anddissipate impact energy and such that said payload is dispersedlaterally through said cylindrical wall in multiple directions uponimpact.
 2. The projectile of claim 1, wherein said foam material has adensity between approximately 8 and 14 pounds per cubic foot.
 3. Theprojectile of claim 1, wherein said payload is chosen from the group ofpayloads consisting of marker agents, lacrimators, irritants,inflammatory agents, odorants and inert powders.
 4. The projectile ofclaim 1, said projectile nose further comprising a rear plug wall joinedto said cylindrical wall, the combination of said forward end, saidcylindrical wall and said rear plug wall defining said nose cavity. 5.The projectile of claim 4, wherein said payload is chosen from the groupof payloads consisting of marker agents, lacrimators, irritants,inflammatory agents, odorants and inert powders.
 6. The projectile ofclaim 4, wherein said rear plug wall is joined to said projectile base.7. The projectile of claim 1, wherein said foam material is apolyurethane.
 8. The projectile of claim 4, wherein said projectile basecomprises a forward wall joined to a base cylindrical wall extendingaway from said projectile nose.
 9. The projectile of claim 8, whereinsaid rear plug wall is joined directly to said forward wall of saidprojectile base.
 10. The projectile of claim 9, wherein said rear plugwall is composed of a resilient, impact-absorbing material.
 11. Theprojectile of claim 4, wherein said rear plug wall is composed of aresilient, impact-absorbing material.
 12. A non-lethal projectilecomprising: a projectile nose composed of a frangible, rigid, polymerfoam material and comprising a cavity; a payload disposed within saidcavity; and a non-frangible projectile base joined to said projectilenose; wherein said projectile nose has a rounded forward end and acylindrical wall, said cylindrical wall being thinner than said forwardend, such that said thinner cylindrical wall breaks prior to saidforward end upon impact to absorb and dissipate impact energy and suchthat said payload is dispersed laterally through said cylindrical wallin multiple directions upon impact.
 13. The projectile of claim 12,wherein said projectile base comprises a forward wall joined to a basecylindrical wall extending away from said projectile nose.
 14. Theprojectile of claim 13, said projectile nose further comprising a rearplug wall joined to said nose cylindrical wall, the combination of saidforward end, said nose cylindrical wall and said rear plug wall definingsaid nose cavity.
 15. The projectile of claim 12, wherein said foammaterial has a density between approximately 8 and 14 pounds per cubicfoot.
 16. The projectile of claim 12, wherein said payload is chosenfrom the group of payloads consisting of marker agents, lacrimators,irritants, inflammatory agents, odorants and inert powders.
 17. Theprojectile of claim 14, wherein said payload is chosen from the group ofpayloads consisting of marker agents, lacrimators, irritants,inflammatory agents, odorants and inert powders.
 18. The projectile ofclaim 14, wherein said rear plug wall is joined to said projectile base.19. The projectile of claim 12, wherein said foam material is apolyurethane.
 20. The projectile of claim 14, wherein said rear plugwall is composed of a resilient, impact-absorbing material.